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| author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2012-01-11 03:08:09 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-11 04:30:44 +0400 |
| commit | 43d2b113241d6797b890318767e0af78e313414b (patch) | |
| tree | 6f25647f2660f8fca63cc8355b70ad643993dab8 /fs/exec.c | |
| parent | 6bd4837de96e7d9f9bf33e59117c24fc230862ac (diff) | |
| download | linux-43d2b113241d6797b890318767e0af78e313414b.tar.xz | |
tracepoint: add tracepoints for debugging oom_score_adj
oom_score_adj is used for guarding processes from OOM-Killer. One of
problem is that it's inherited at fork(). When a daemon set oom_score_adj
and make children, it's hard to know where the value is set.
This patch adds some tracepoints useful for debugging. This patch adds
3 trace points.
- creating new task
- renaming a task (exec)
- set oom_score_adj
To debug, users need to enable some trace pointer. Maybe filtering is useful as
# EVENT=/sys/kernel/debug/tracing/events/task/
# echo "oom_score_adj != 0" > $EVENT/task_newtask/filter
# echo "oom_score_adj != 0" > $EVENT/task_rename/filter
# echo 1 > $EVENT/enable
# EVENT=/sys/kernel/debug/tracing/events/oom/
# echo 1 > $EVENT/enable
output will be like this.
# grep oom /sys/kernel/debug/tracing/trace
bash-7699 [007] d..3 5140.744510: oom_score_adj_update: pid=7699 comm=bash oom_score_adj=-1000
bash-7699 [007] ...1 5151.818022: task_newtask: pid=7729 comm=bash clone_flags=1200011 oom_score_adj=-1000
ls-7729 [003] ...2 5151.818504: task_rename: pid=7729 oldcomm=bash newcomm=ls oom_score_adj=-1000
bash-7699 [002] ...1 5175.701468: task_newtask: pid=7730 comm=bash clone_flags=1200011 oom_score_adj=-1000
grep-7730 [007] ...2 5175.701993: task_rename: pid=7730 oldcomm=bash newcomm=grep oom_score_adj=-1000
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/exec.c b/fs/exec.c index 3f64b9f26e7d..aeb135c7ff5c 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -59,6 +59,8 @@ #include <asm/uaccess.h> #include <asm/mmu_context.h> #include <asm/tlb.h> + +#include <trace/events/task.h> #include "internal.h" int core_uses_pid; @@ -1054,6 +1056,8 @@ void set_task_comm(struct task_struct *tsk, char *buf) { task_lock(tsk); + trace_task_rename(tsk, buf); + /* * Threads may access current->comm without holding * the task lock, so write the string carefully. |